In recent years, a projector that projects an image on a screen has been widely used not only at an office but also at home. The projector modulates light from a light source by a light valve (light modulation element) to generate image light, and projects the image light on the screen to perform display. In recent years, a palm-sized small projector using a solid-state light emitting element such as an LED (Light Emitting Diode) or an LD (Laser Diode) as a light source, a mobile phone including the small projector, and the like have started to be widely used.